Focused ion beams (FIBs) are used in a variety of nanoscience and technology applications such as micromachining and nanofabrication of semiconductor chips. For example, focused ion beams are currently used for applications such as maskless implantation into semiconductor materials, lithographic mask repair for visible light and X-rays, high precision machining of mesoscopic structures, deposition of materials from the vapor phase by ion-induced deposition, modification of integrated circuits, failure analysis for integrated circuit manufacturing process, surface analysis, transmission electron microscope (TEM) sample preparation, microscopy, secondary ion mass spectroscopy, and micro and nano electromechanical systems.
Certain commercially available FIB systems are based on liquid metal ion sources (LMIS) and are capable of providing focused ion beams of only gallium (Ga) ions. However, this limits the applicability and functionality of the generated focused ion beams in areas where FIBs of other elements are required.
Moreover, application of FIBs generated using gallium ions onto a substrate may have contamination issues associated with them due to gallium ions that may embed into the substrate often altering electrical and magnetic properties of the fabricated devices. In certain systems, the application of heavier mass of gallium ions on a substrate results in impact induced damage while carrying out circuit modifications on the devices and may also lead to excessive absorption of ultraviolet (UV) light by implanted gallium ions during photo-mask repair.
In certain FIB systems, gas field ion sources are used to produce gaseous ions. However, the tip surface of the system is required to be cooled to cryogenic temperatures for effective ionization. Moreover, such sources are limited to use with light ions and the current yield of these systems is substantially low.
Furthermore, FIBs generated using the conventional LMIS FIB systems provide substantially low currents thereby resulting in substantially low turnover times for performing volume processes. Improved FIBs and methods for their production and use are desirable.